A magazine is an ammunition storage and feeding device within, or attached to, a repeating firearm. The magazine functions by moving the cartridges stored in the magazine into a position where they may be chambered by the action of the firearm. Most magazines designed for use with a reciprocating bolt firearm utilize a set of feed lips which stops the vertical motion of the cartridges out of the magazine but allows one cartridge at a time to be pushed forward (stripped) out of the feed lips by the firearm's bolt into the chamber.
Some form of spring and follower combination is almost always used to feed cartridges to the lips, which can be located either in the magazine (most removable box magazines) or built into the firearm (fixed box magazines). As the firearm cycles, cartridges are moved to the top of the magazine by a follower driven by spring compression to a feed position. In most firearms, the magazine follower engages a slide-stop to hold the slide back and keep the firearm out of battery when the magazine is empty and all rounds have been fired. Box magazines may be integral to the firearm or removable.
A detachable box magazine is a self-contained mechanism capable of being loaded or unloaded while detached from the host firearm. They are inserted into a magazine well in the firearm receiver usually below the action, but occasionally positioned to the side or on top. When the magazine is empty, it can be detached from the firearm and replaced by another full magazine. This significantly speeds the process of reloading, allowing the operator quick access to ammunition.
Conventional pistol box magazines, such as the prior art 45 ACP magazine 100 shown in FIG. 1, have a spring plate 116 with a downwardly protruding pin 120 that protrudes into a hole 122 in the floor plate 118 to prevent removal of the floor plate. In order to remove the floor plate from the magazine body 112, a punch (not shown) is used to press upwards on the button to disengage the spring plate from the floor plate. The magazine floor plate can then be slid forward toward the front of the magazine and disengaged from the rails 124 on the bottom 126 of the magazine. This process has the disadvantage of requiring a tool in order to remove the floor plate. There is also a risk of forcible ejection of the spring plate by the compressed magazine spring 114 once the floor plate is disengaged from the magazine. Conventional 45 ACP magazines are also limited to seven rounds because the spring plate and follower occupy a portion of the interior volume of the magazine.
Conventional rifle box magazines, such as the prior art AR-15 magazine 200 shown in FIGS. 2A & 2B, has a floor plate 214 with an upward protrusion 218 near the front 216. The upward protrusion limits forward movement of the floor plate with respect to the magazine body 212. The floor plate is the same width as the magazine body. In order to remove the floor plate, a screwdriver 222 is inserted into the gap 224 between the front edge 226 of the floor plate and the bottom edge 228 of the magazine 212. The floor plate is thin and flexible enough that the front edge of the floor plate is pushed down to flex the floor plate so the upward protrusion can clear the front edge of the magazine body as the floor plate is pried forward. This is enabled by the bent tabs that support the plate from below being spaced away from the front face of the magazine, providing an elongated flexible cantilever that give significant flexing to allow the protrusion to clear the front edge. The floor plate can then be slid forward to disengage the floor plate from the tabs 220 on the bottom of the magazine. Also, the magazine body is directly above the plate about the entire periphery, so that it cannot be pressed upward into the opening, even in the absence of spring pressure, and must be flexed to clear the protrusion.
It is often desirable to increase the carrying capacity of a magazine. This is sometimes achieved by adding an extension to the lower end of the magazine, but this is often considered undesirable. Existing attempts to add capacity may exploit marginal available space while keeping convention floor plate dimensions, but this can have disadvantages. For instance, eight-round magazines are offered for conventional Model 1911 pistol single-stack magazines without an extension, but these pack the rounds in so tightly that they do not let the rounds depress. As a result, a loaded magazine may be installed only when the pistol slide is retracted, because loading a full magazine when the slide is closed requires the stripper on the slide to be able to depress the rounds slightly. Consequently, such magazines are unable to carry eight rounds plus one in the chamber of the associated firearm.
Therefore, a need exists for a new and improved magazine floor plate that can be removed from a magazine without tools, eliminates the need for a spring plate, and enables a magazine to carry eight rounds with an additional round in the associated firearm's chamber. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the magazine floor plate according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of providing a magazine floor plate that can be removed from a magazine without tools, eliminates the need for a spring plate, and enables a magazine to carry eight rounds with an additional round in the associated firearm's chamber.